Field of the Invention
The present disclosure relates to a lens moving device, a camera module, and an optical apparatus.
Background of the Related Art
A camera module may include an image sensor, a printed circuit board configured to deliver electric signals to the image installed on the printed circuit board, an infrared cut-off filter configured to block light in infrared area from incident into the image sensor, and an optical system including at least one lens configured to deliver an image to the image sensor. Here, a lens moving device configured to perform auto-focusing function and handshake compensation function may be installed in the optical system.
The lens moving device may be formed in a variety of ways. In general, a voice coil motor is commonly used in the lens moving device. The voice coil motor operates by an electromagnetic interaction between a magnet fixed in a housing and a coil unit wound on an outer circumferential surface of a bobbin coupled with a lens barrel. The voice coil motor may perform auto-focusing function. An actuator module of such voice coil motor may reciprocatively move in a direction parallel to an optical axis whereby a bobbin an up and down motion is elastically supported by an upper and a lower elastic member.
Recently, there has been a requirement to develop a lens moving device configured to detect an optimal focusing position by receiving a location information of a bobbin installed with a lens as a feedback. However, there is still a risk of performance degradation such as disequilibration of electromagnetic force, eccentricity of lens barrel due to magnetic force, etc.